Characteristics, burden of illness, and physical functioning of patients with relapsing-remitting and secondary progressive multiple sclerosis: a cross-sectional US survey

Background: Although most patients with relapsing-remitting multiple sclerosis (RRMS) will develop secondary progressive multiple sclerosis (SPMS), little is known about the burden of multiple sclerosis by disease subtype. This study describes the burden of disease in terms of demographics, disease severity, symptoms, health care resource and disease-modifying therapy (DMT) utilization, work and activity impairment, and physical functioning of SPMS and RRMS patients. Methods: SPMS and RRMS patient responses from the 2012 and 2013 waves of the US National Health and Wellness Survey were evaluated to detect differences in demographics, disease severity, symptoms, and health care resource and DMT utilization. In addition, data from the Work Productivity and Activity Impairment and Short Form-36 questionnaires were analyzed. Results: SPMS patients were older than RRMS patients (mean age 55.7 vs 48.9 years; P<0.001); a lower proportion were female (56.2% with SPMS vs 71.6% with RRMS; P=0.002), and fewer SPMS than RRMS patients were employed (20.0% vs 39.7%; P<0.001). SPMS patients described their disease as more severe, reporting several neurological symptoms more frequently and higher hospitalization rates than RRMS patients. A lower percentage of SPMS than RRMS patients reported DMT use. SPMS patients had greater overall work and activity impairment than RRMS patients. After controlling for baseline characteristics, impairment in physical functioning was greater in SPMS patients. Conclusion: Overall, SPMS patients had a higher burden of illness than RRMS patients, under-scoring the need to treat RRMS patients early to delay disability progressing using therapies that are effective in real-world settings.